Bottom Line:
At every age, a second CI is very effective.These results may show important binaural effectiveness such as binaural summation and head shadow effect.Bilateral CI is very useful medical intervention for many children with severe-to-profound hearing loss in Japan as well as elsewhere.

Objectives: The number of patients with bilateral cochlear implant (CI) has gradually increased as patients and/or parents recognize its effectiveness. The purpose of this report is to evaluate the efficacy of 29 bilateral CI out of 169 pediatric CI users, who received auditory-verbal/oral habilitation at our hearing center.

Results: Binaural hearing using bilateral CI is better than first CI in all speech understanding tests. Especially, there were significant differences between the results of first CI and bilateral CI on SDS at 70 dB SPL (P=0.02), SDS at 1 m from second CI side SP at 60 dB SPL (P=0.02), word recognition score (WRS) at 1 m from second CI side SP at 60 dB SPL (P=0.02), speech discrimination score (SDS) at 1 m from front SP under the noise (S/N=80/70; P=0.01) and WRS at 1 m from front SP under the noise (S/N=80/70; P=0.002). At every age, a second CI is very effective. However, the results of under 9 years old were better than of over 9 years old on the mean SDS under the noise (S/N=80/70) on second CI (P=0.04). About use of a hearing aid (HA) in their opposite side of first CI, on the WRS and SDS under the noise, there were significant differences between the group of over 3 years and the group of under 10 months of HA non user before second CI.

Conclusion: These results may show important binaural effectiveness such as binaural summation and head shadow effect. Bilateral CI is very useful medical intervention for many children with severe-to-profound hearing loss in Japan as well as elsewhere.

Figure 2: Interval between first and second cochlear implantation (month).

Mentions:
Since we started CI surgery in 1997, out of 169 children undergoing CI rehabilitation in our clinic, 29 children (17%) had bilateral CI for at least half a year before May 2011. The age of the children at the first CI operation ranged from 1 year 4 months to 15 years 5 months, whereas the age of children at the second CI operation ranged from 2 year 1 month to 15 years 10 months (Fig. 1). The most common age for the first CI was 1 or 2 years. The interval between first and second CI fitting ranged from 5 months to 10 years 1 month. This can be considered a relatively wide range, but the most frequent interval between the two CIs was under 1 year (Fig. 2). The period on non-use of their HA before the second CI is also valuable: it ranges from 0 month to 108 months (9 years). Twelve cases did not remove their HA before the second CI (Fig. 3). Causes for deafness were described in Fig. 4. The devices used are described in Fig. 5.

Figure 2: Interval between first and second cochlear implantation (month).

Mentions:
Since we started CI surgery in 1997, out of 169 children undergoing CI rehabilitation in our clinic, 29 children (17%) had bilateral CI for at least half a year before May 2011. The age of the children at the first CI operation ranged from 1 year 4 months to 15 years 5 months, whereas the age of children at the second CI operation ranged from 2 year 1 month to 15 years 10 months (Fig. 1). The most common age for the first CI was 1 or 2 years. The interval between first and second CI fitting ranged from 5 months to 10 years 1 month. This can be considered a relatively wide range, but the most frequent interval between the two CIs was under 1 year (Fig. 2). The period on non-use of their HA before the second CI is also valuable: it ranges from 0 month to 108 months (9 years). Twelve cases did not remove their HA before the second CI (Fig. 3). Causes for deafness were described in Fig. 4. The devices used are described in Fig. 5.

Bottom Line:
At every age, a second CI is very effective.These results may show important binaural effectiveness such as binaural summation and head shadow effect.Bilateral CI is very useful medical intervention for many children with severe-to-profound hearing loss in Japan as well as elsewhere.

Objectives: The number of patients with bilateral cochlear implant (CI) has gradually increased as patients and/or parents recognize its effectiveness. The purpose of this report is to evaluate the efficacy of 29 bilateral CI out of 169 pediatric CI users, who received auditory-verbal/oral habilitation at our hearing center.

Results: Binaural hearing using bilateral CI is better than first CI in all speech understanding tests. Especially, there were significant differences between the results of first CI and bilateral CI on SDS at 70 dB SPL (P=0.02), SDS at 1 m from second CI side SP at 60 dB SPL (P=0.02), word recognition score (WRS) at 1 m from second CI side SP at 60 dB SPL (P=0.02), speech discrimination score (SDS) at 1 m from front SP under the noise (S/N=80/70; P=0.01) and WRS at 1 m from front SP under the noise (S/N=80/70; P=0.002). At every age, a second CI is very effective. However, the results of under 9 years old were better than of over 9 years old on the mean SDS under the noise (S/N=80/70) on second CI (P=0.04). About use of a hearing aid (HA) in their opposite side of first CI, on the WRS and SDS under the noise, there were significant differences between the group of over 3 years and the group of under 10 months of HA non user before second CI.

Conclusion: These results may show important binaural effectiveness such as binaural summation and head shadow effect. Bilateral CI is very useful medical intervention for many children with severe-to-profound hearing loss in Japan as well as elsewhere.